Improvement in tin-coated steel bed-springs



'L..C. BUYINGTUN.

Tin Coated Steel Bed-Springs.

N0154742. Patented Sept.8,'1874..

WI'TNESSES INVENTOR process for the UNITED STATES PATENT QEEIGE.

LEVI C. BOYINGTON, OF CHICAGO, ILLINOIS.

IMPROV'EMENTAIN TIN-COATED STEEL BED-SPRINGS.

Specification forming part of Letters Patent N o. 154,742, datedSeptember 8, 1874; application filed v January 31, 1874.

ing hadvto the accompanying drawing, representing a steel spiral springembodying my invention.

The object of my invention is to prevent steel spiral springs fro'mbecoming rusty when -exposed, and to accomplish this result by means ofa cheap and ornamental coating, which may be readily applied to thesurface of the springs without destroying their dexibility. To this endmy invention consists of a steel spiral spring provided with a coatingof tin, applied to its surface by means of any suitable process whichwill not injure the flexibility of the spring.

I deem it preferable to employ the following purpose of enameling thespring :4 I form the spring', in any known manner, from soft steel wire,as hard steel wire would be tool 'stiff and brittle for that purpose,and the spring is then dipped into muriatic acid diluted with zinc untilthe acid will take no more. combination of melted lead and tin,inpropontions of one of lead to two of tin. As the spring, on beingremoved from the metallic bath, would be too soft for durable use as aspiral spring, it is immediately, on being removed froln said metallicbath, immersed in oil or water to harden and temper it. When a brighterand smoother coating is desired, the spring, after receiving its firstcoating, and before being tempered in the manner described, is dippedinto a second vessel containing melted tin and oil. The tempering canthen be done, as described.

It is ther dipped into a' The spring, when taken `from the molten leadand tin, `or from the molten tin and oil, is as hot as would be requiredif it were to be heated in a lire for the purpose of being tem- V pered,and is hardened equally as much as it would be if tempered in the lattermanner, and much more evenly, for the reason that when heated in a bathof molten metal the heat is more evenly distributed.

I am aware that iron and steel wire have been tinned and hardened at thetime of drawing the wire, but I am not aware that atinned steel spiralspring has ever before been made or sold as an article of merchandise.Hard or tempered tinned steel wire could not be formed into a spiralspring having a perfect face, and salable as an article of merchandise,without first drawing its temper, and, when the temper is drawn fromhard steel wire, so that it may be formed into a spiral spring, as alsosoft steel tinned wire, would not be useful and durable as a spiralspring without being tempered, as hereinbefore described, after being'formed as a spiral spring.

In the drawing, A represents a steel spiral spring provided with acoating of tin in the manner described. u

Having thus described my invention, what I claim as new, and desire tosecure by.Letters Patent, is-

1. A new article of manufacture, consisting of a steel spiral springprovided with a coating of tin, for the purpose specified.

2. In the manufacture of steel spiral springs, the process of irstmaking the springs o f steel wire sufciently soft to be bent in the formrequired, and afterward providing them with a coating of tin andtempering them, in the manner described.

LEVI C. BOYINGTON.

Witnesses:

N. C. GEIDLEY, F. F..WARNEE.

